Trends in the St. John’s wort (Hypericum perforatum) research literature: a bibliometric analysis

Objectives St. John’s wort (Hypericum perforatum) has been used in traditional medicine for centuries for different conditions, including kidney and lung ailments, insomnia, depression, and to aid wound healing. The objective of the present bibliometric analysis is to capture the characteristics of research publications on the topic of St. John’s wort. Methods Searches were run on April 09, 2021, and results were exported on the same day to prevent discrepancies between daily database updates. Trends associated with this subset of publications were identified and presented. Bibliometric networks were constructed and visualized using the software tool VOSviewer. Results A total of 1,970 publications were published by 5,849 authors across 961 journals from 1859 to 2021. Beginning in the late 1990s, a steep increase was found in the volume of publication on this topic. The journal that published the largest number of publications was Phytotherapy Research. The most productive countries included Germany and the United States. Conclusions The present study provides the characteristics of the St. John’s wort literature that allows understanding of the past, present, and future of research in this area. It is a useful evidence-based framework on which to base future research actions and academic directions.

ELECTROSPINNING OF ST. JOHN'S WORT OIL LOADED MICROCAPSULES BASED PVA NANOFIBERS

In this study, it was achieved that the production of St. John's Wort oil loadad Eudragit RS 100/PVA microcapsules by emulsion/solvent evaporation method and the microcapsules were embedded in PVA nanofibers. Morphological analysis was carried out with SEM images of both microcapsules and nanofibers. The presence of St. John's Wort oil, PVA and Eudragit RS 100 polymers were confirmed in the chemical structure of microcapsules and nanofibers by FT-IR. According to experimental studies, microcapsules were produced to have a smooth surface, a spherical shape and a uniform particle size. The PVA concentration was kept constant at 10% wt and microcapsule concentrations were applied as 1, 3, 5, 7, and 9 wt %. Then, polymer solution properties were measured, such as conductivity, viscosity, and surface tension. It was determined that viscosity and surface tension values increased with microcapsule concentration increase, while conductivity did not change significantly. Nanofiber production was realized via the electrospinning method under the optimum process parameters. According to the SEM images and histogram, nanowebs have a fine fiber diameter, smooth surface, high quality and no bead structure. In addition, the average microcapsule size is 30 μm, average fiber diameter is 430 nm and the fiber diameter uniformity coefficient is 1,014. It is thought that this nanofiber surface containing microcapsules embedded in St. John's Wort has the potential to be used as a wound dressing.